9.2.7. The compression procedure shall be as follows:(a) when a person is in the intermediate air lock, the air pressure shall be uniformly applied and shall not exceed 35 kPa during the first 2 minutes of application;
(b) the pressure shall not be raised to more than 35 kPa until it has been ascertained that any person in the air lock is free from discomfort due to air pressure; and
(c) the air pressure may then be raised in the air lock at a rate not exceeding 35 kPa per minute subject to the condition stipulated in paragraph b.